Compactors are typically used to compact material, such as hot asphalt, loose gravel, soil or other material. While compactors can be constructed in a variety of configurations, generally, compactors are vehicles including one or more cylindrically shaped drums that function as wheels that compress material underneath. The drums may have a smooth surface, or may include features, such as teeth, depending on the material to be compacted. For example, in paving roads typically an asphalt paver spreads hot, loose asphalt approximately to a desired grade. The asphalt paver is then followed by a compactor having one or more smooth-surfaced drums, which rolls over the loose asphalt, thereby compacting it to a hard surface. This process may be repeated several times in a series of layers until a final desired grade is reached. By way of further example, gravel or other material may be spread to an approximate grade and then compacted by a compactor.
In order to provide efficient operation of the compactor, it is desirable to provide the operator with visibility of the maximum width of the drum surface. Not only does good visibility of outer drum edges allow an operator to determine precisely the area that he or she is compacting, it allows the operator to ensure that the drum surface remains clean, such that the compactor provides the desired surface quality to the compacted material. For example, because hot asphalt is generally sticky, asphalt can stick to the surface of a drum of the compactor instead of being compacted with the rest of the asphalt, resulting in voids in the asphalt surface. Thus, it is desirable for the operator of the compactor to be able to see the outer drum surface in order to determine whether asphalt or other material is sticking to the drum and, if necessary, take appropriate corrective action. Moreover, compactors often include sprayers that maintain a wet outer drum surface in order to minimize the opportunity for asphalt or other material to stick to the drum. Maximum visibility of the width of the drum surface allows the operator to determine whether the sprayers are functioning properly in order to deter asphalt from adhering to the drum surface.
The drums of compactors are typically operated hydraulically with hoses extending from one or more control valves located in the interior of the compactor to a hydraulic drive unit located in the interior of the drum. To withstand high pressures common in hydraulic systems, hydraulic hoses associated with the hydraulic systems of compactors must be robust, and, as a result, often have limited bending or arcing radii. Depending upon the hose routing, the hydraulic hoses may present obstacles to the visibility of the drum surfaces, particularly toward the outer drum edges.
In order to pass through the frame of the compactor to the control valve, various fittings are often used to compensate for the large bending radius of the hoses as well to allow passage of hydraulic fluid through the frame of the compactor from the compactor's exterior to its interior. For example, bulkhead fittings (“bulkheads” for short) are fittings designed to allow the passage of hydraulic fluid through a wall, such as through a metal plate of a compactor frame. Generally, a bulkhead is a hollow cylinder configured to extend completely through a hole in the wall and connect to a hose at each end, such as by threads, a quick-connect mechanism, or other mechanism. Because hydraulic hoses generally terminate in a fitting, such as a male or female connector, that is wider than the outer diameter of the hose, passing a hose through a hole in the frame without a bulkhead would typically result in undesirable wear to the outer surface of the hose. Rather than bending a hydraulic hose in a wide arc in order to guide it to a bulkhead, 90-degree fittings or other degree bends are often used to allow a hydraulic routing to make sharper turns than would be possible by simply arcing a hose.
The inclusion of multiple fittings in a hydraulic routing increases labor costs associated not only with initial installation, but also with integrity testing and ongoing maintenance. Once the compactor is assembled, each connection of a fitting to the corresponding routing requires testing to ensure that the hydraulic system does not leak. Moreover, each fitting connection is a potential location for a future leak during the life cycle of the compactor. Accordingly, it is desirable to minimize the amount of fittings used. In order to minimize production costs, it is further desirable that frame of a compactor be usable with various widths of rollers.